This invention concerns a push button switch, particularly, a master, or power, switch, having: housing-affixed contacts and at least one contact bridge for bridging the contacts that is movable by means of a spring plunger; an over-center spring-switching mechanism that is operatively coupled between the spring plunger and a manually-movable sliding switch; and a sliding locking linkage for the sliding switch which includes a groove and a follower peg which engages in the groove, whereby the sliding switch, upon being depressed against the force of a return spring, shoves the first locking part along the second locking part and alternately changes between "on" and "off" positions.
Such switches are often used for controlling electrical power to consumer appliances, particularly television-like devices.
German Auslegeschrift DE-AS 1 590 503 discloses such a push button switch. The locking device disclosed therein is part of an engaging spring which is mounted on a housing and which engages a groove in a sliding switch.
Similar push button switches are disclosed German patent publications DE 35 45 938 A1, DE-AS 1 300 603, DE-PS 1 690 203, DE-OS 20 65 104, DE-AS 21 16 776, DE-OS 31 50 046 and DE-OS 33 32 371. In all of these push button switches the problem exists that when the respective sliding switch is forcibly loaded in a direction opposite to its normal manual depression direction, the danger arises that a locking linkage thereof will be damaged. One must consider that such improper manipulations will be made because consumers do not always know, from the beginning, proper operating procedures. The danger of damaging the push button switches upon forcible improper manipulations thereof also arises because sliding locking linkages must be constructed to be quite small and are usually of resinous plastic material; thus, it cannot be assumed that all parts, without further measures, are arranged to be sufficiently sturdy that they can withstand forceful improper manipulations.
German Patent DE-PS 36 44 437 discloses a push button switch with a gliding, or sliding, locking linkage in which a locking, or sliding, element is shiftably held by means of a spring. This spring device protects the locking linkage from overloading in a keying, or depressing, direction.
It is an object of this invention to provide a push button switch of the type mentioned in the first paragraph of the "BACKGROUND OF THE INVENTION" above in which, upon a manual loading of the push button switch in a direction opposite to a keying, or depressing direction, the danger that the locking linkage will be damaged does not arise.